Session的学习

由上一篇文章我们已经知道session的概念，接下来一个图解释session的工作原理

一、创建Session

package test;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class SetSession
 */
@WebServlet("/SetSession")
public class SetSession extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public SetSession() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		HttpSession session=request.getSession();
		session.setAttribute("username","lsa");
		session.setAttribute("sex","gril" );
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

二、得到session

 

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//创建或者设置session
		HttpSession session=request.getSession();
		String name=(String) session.getAttribute("username");
		String sex=(String) session.getAttribute("sex");
		System.out.println(name);
		System.out.println(sex);
		//删除session
		session.removeAttribute("username");
		String name1=(String) session.getAttribute("username");
		String sex1=(String) session.getAttribute("sex");
		System.out.println(name1);
		System.out.println(sex1);
		//删除session
		//session.removeAttribute("username");
		//销毁session
		//session.invalidate();
	}